TrueNet measures the speed which internet companies offer their users and produces monthly reports for the public.

TelstraClear's cable service, which is only available in Wellington and Christchurch, is consistently faster than other offerings in TrueNet tests but the new Vodafone acquisition also beat out rivals in the copper-line DSL market last month, jumping up from 4th place in November.

TelstraClear, Maxnet, Slingshot, and Vodafone all loaded TrueNet's test page in under 0.5 seconds in December.

Telecom downloaded the test page in just over a second while Orcon was closer to 1.5 seconds.

In a separate set of testing, TrueNet said Orcon, Snap and Telecom offered customers the most consistent internet speeds during periods of heavy use in December,.

TrueNet found Orcon, Snap and Telecom all provided customers with minimum speeds above 97 per cent of the top speeds users experienced.

According to TrueNet, this measure can be used to compare the performance of each internet company during peak usage periods of the day.

Vodafone provided users a minimum speed above 88 per cent of its best speed, while its new subsidiary TelstraClear fared slightly better at 89 per cent.

The report said most internet companies had "improved significantly" in this area between March and December last year, with Orcon up by 9 per cent and TelstraClear improving 13 per cent.

Vodafone got the green light from the Commerce Commission for its $840 million takeover of TelstraClear late last year. Although the sale was announced last July it needed permission from the regulator before it could go ahead.